Motor control system



x 70cm P. s. DlcKEY K MOTOR CONTROL SYSTEM l Y Feb. 11: 1941-'SUBSTITUTE FOR Mrssmem v 2 sheets-sneer 1M Filed July 2, 1938 1Illlsi...

n (Ittmmegy Feb.11,1941. Raman q 2,231,569

MOTOR CONTROL SYSTEM Filed .July 2. 1938 ashets-sneet Fis. 5

PAUL vs` olcKEY Patented Feb. 11, 1941 UNITEDy STATES PATENT ori-icalrMoron cgrrli. srs'rsM V *l l l Paul Dickey, cleveland, obit, assignerto Bailey Meter Company, a. corporation of Del- Swart 8 Claims.

This invention relates to motor control systems for use in regulating orcontrolling anyl electric, chemical, thermal, physical, or othervariable quantity or condition or relation, and which may be through thecontrol oi a correotive agent or agents. While I have illustrated anddescribed my invention as relating to control systems wherein electricalenergy is utilized as the motive power for actuating devices to controlthe rate of application of an agent orthe value of a variable, it is tobe understood that this is illustrative only. l Y

An obJect of the invention is-to provide an apparatus capable oftransmitting and receiving impulses representative of the value of thevariable quantity or condition.'

A further object is to provide a telemetric system wherein a pluralityof transmitters are eiective upon a single receiver which isdifferentially responsive to the duration and sense of the signalscyclically transmitted by the plurality of transmitters. g

With these and other objects in view I will now describe the drawings inwhich is represented a preferred embodiment of my invention.

` Fig. 1 is a somewhat diagrammatic arrangement of a preferredembodiment of my invention.

Fig. 2 is a side elevation of a relay. Fig. 3 is a plan view of therelay of Fig. 2. Fig. 4 is a simplified wiring diagram of the g relayillustrated in Figs. 2 and 3.

Fig. 5 is a simplified wiring diagram of another form of relay.

Referring now to Fig. 1, I indicate at I a. conduit through which afluid is owingin the direction of the arrow. A damper 2 may bepositioned in the conduit to regulate the pressure of the uid, whichpressure is effective in positioning a Bourdon tube 3 having anindicator arm 4 moved relative to' an index Ei.k The Bour- 'don tube 3is pivotally connected to angularly position a member i0 through links8, 1 and beam 8. The beam 8 is provided with a movable iulcrum wherebythrough the agency of a threaded screw S the moment arm of the beam 8adjacent the link 6 may be varied relative to the moment arm adjacentthe link 1, and thus the angular movement transmitted to the membet i0for each increment o! movement of the pointer l relative to the index 5may be varied as desired by movement ot the screw 9. An adjusting screwIl is also provided whereby thek actual angular position of the memberl0 may be varied for any given position o1' the indicae tor arm I. Toaccomplish this the screwr H raises or lowers the ulcrum, thuspositioning the beam 8 in a clockwise or csunterclockwise directionaround the lower pivot end of the link 6.

I indicate at i2 a transmitter having a lcontinuously rotated time cami3 rotated by a synchronous alternating current motor i4 connected bythe conductors i5, I6 with a power source il. Riding on the periphery ofthe time cam i3 is a roller carried at the free end of a pivoted varmi8, which arm carries a contact I9 connected to a conductor 20. Y

. A- second pivoted arm 2i has contact portions 22, 23 and is connectedto a. conductor M.` A

screw 25 is threaded through the arm 2i and provides a stop whereby thearm 2i. normally by gravity, rests at a lower position determined by theangular position of the member i0 around its pivot. l'n other words, asthe member `il) is moved in clockwise or counterclockwise direction,being positioned through the movement of the Bourdon tube 3. it (throughengagement with the screw 25) positions the arm 2i around it pivot.

A third pivoted arm 26 carries a contact 21 adapted to cooperate withthe contact 23 and connected to the conductor i6. The normal position(of gravity rest) of the arm 26 is with its free end against a stop 2B.

rI'he time cam i3 periodically positions the arm Vi8 around its pivotuntil the contacts i9, 22 engage, thus making connection between theconductors 20, 24. Additional rotation 'of the cam. i3 carries the arm2i upwardly until the contacts 23, 2l engage, thus closing circuitbetween the conductors I6, 24. It will be observed that in each cycle ofthe cam i3 the dura.-

tion ofl the contact closure I9, 22 and correspondingly of the signaloriginated thereby is determined by the initial position of the armill,r which in turn is determined by theposition of the member in,related to the position of the Bourdon tube 3, and thereby directlyrelated to the value of the variable quantity, in this case the pressureof the iiuid within the conduit l. 'I'hus the duration of the principalsignal initiated by the transmitter l2 is directly representative of orproportional to a variable quantity..

A second transmitter 29 is quite similar in con-v struction. A time cam30 is continuously ro- A pivoted contact arm 3l ls shown in normallyclose-circuited position,- connecting one side of `vide two pair ofcontacts arranged in parallel .to connect` the conductor 33 of the motor3| to the same source of alternating current will rotate at the samespeed. However, there is a possibility that the two time cams i3, 3Dmight be out of proper phase relationship through the initial startingor some accidental stopping of one of the cams relative to the other.

So long as the cams are in proper phase relation then the motor winding3|, under control of the contact arms 26, 34will not be deenergized andthe cams 30, i3 will rotate in phase relation with each other. If,however, for some reason the angular position of the cam 3D relative tothe cam i3 is different therefrom, then there may occur in a givencyclean open'circuiting of the winding 3| by the contact arm 34 while thecontacts 23, 21 are open, and thus rotation of the cam 36 would behalted until the cam i3 rotated about and was again in phase relationwith the cam 3U, whereupon the lmotor 3| would restart and the two camsproceed in proper phase relation.

At I indicate in general a receiver which i takes the general form of arelay device having an alternating current synchronous torque mov vtordiiferentially responsive to the duration and ously energized directlyacross the power source direction or the other of energization of theshading coil 38 relative to the shading coil 31, then rotation of therotor will occur in a predetermined direction and for a time extentdetermined by the time length of the overlap. Thus the angular movementof the rotor is in accordance with the algebraic summation of signalsperiodically initiated at the transmitters i2. 29 and effective inenergizing the shading coils 31. 38. This is accomplished as follows:

'I'ne shading coil 31 is connected through the conductor 20 to thecontact arm i8 of the transmitter i2. The shading coil 38 is connectedthrough a conductor 38 with a similar pivoted arm 40 in the transmitter28. The neutral o! the shading coils A31, 38 is connected through aconductor 4| with the conductor 24 through a mercury switch 42. Thelatter is adapted to be positioned by the motor 3l -to open its circuitat a predetermined point and over a predetermined portion o! rotation ofthe cam 30.

In the transmitter 29 is also located a pivoted contact arm 43,generally similar to the contact arm 2| of transmitter i2, and which isadapted under certain conditions to cause a closing of circuit betweenthe conductors 24, 39. Such closure of circuit is for a duration of eachrevolution of the cam 35 determined by the position oi the pivoted arir.44 in a manner similar to that described ior transmitter i2 and themember. i0.

Itwill now be observed that a circuit closure oi' the contacts i9, 22 atthe transmitter |2 will short out the shading coil 31 (assuming themercury switch 42 is close-circuited) while closure of the contacts 66,61 will short out the shading coil 38. Ii the positions of the contactarms 2|, 43 relative to the arms i8. 40 are the same, then the shadingcoils 31, 38 will be short-ed out for identical portions of each timecycle and induced current will flow through the two shading coils forthe same period of time. Likewise, throughout the remainder of the timecycle the shading coils 31, 38 will be open circuitcd. Thus there willbe no urge by either of the shading coils 31 or 38 to cause rotation ofthe rotor. If, however, circuit closure at i9, 22 is of longer durationthan at 66, 61, then there will be an overlap of close cii'cuiting ofthe shading coil 31 beyond the portion of the time cycle when the'coil38 is close circulted, and for such period of overlap the motor in thereceiving device 35 will be urged l to angular movement in predetermineddirection.

' 56, 61, but the period of energization of the shading coils 31, 38will be terminated simultaneously through open circuiting of the mercuryswitch 42 at a. predetermined point of the periphery of the cam 30.

Referring now to Figs. 2 and 3, I illustrate therein more nearly thepreferred structural form and arrangement of the relay 35. Analternating current synchronous motor having a continuously energizedfield winding 36 is provided with suitable laminations 45 and twoopposed shading coils 31, 38. The motor has a rotor 46 on which ismounted an eccentric or cam 41 normally positioned by gravity, asillustrated in Fig. 2, with the greatest eccentricity downwardly. Uponan imbalance in energization of the shading coils 31, 38 the rotor 46will be urged to rotation in one direction or the other and carry.

with it the eccentric 41.

The eccentric is adapted, in its angular positioning, to engage theunderside of the free end of the pivoted leaf members 48, 49 whichnormaliyvrest by gravity againstv thevilxed -stops 59, 5l, Carried onand by the leaf members 48. 49 are mercury switches 52, 53.

Assume that the eccentric 41 is urged to angular positioning in aclockwise direction. After having traversed a predetermined angularamount from the position of rest as shown in Flg.- 2, in its rise theeccentric will engage the underside of the tree end of the leaf member48. carrying the leaf member in angular counterclockwise movement untilthe leaf member engages an upper stop 54 to limit its counterclockwiserotation. In like manner clockwise movement of the leaf member 49 ispossibleuntil it engages an upper stop 55. y

It the leaf member 48 and the mercury switch 52 carried tnereby, ispositioned upwardly until the stop 54 is engaged, and the unequalenergizetion of the shading coils 31, 3B persists, then the eccentric 41will hold the leaf member 48 against Vr:53,231,569 l -V 3 thepossibility of selectively or simultaneously' close-circuiting theshading coils 31, 38. In like manner, a self-starting synchronous motorhaving opposed eld windings is illustrated diagrammatically in Fig. 5,wherein either, or both, or neither of the field windings 56, 5l maybeselectively energized. If both of the field windings are energized, ordeenergized, then the rotor is not urged to rotation. If one only of thefield windings 55, 5l is energized, then the rotor is urged to rotationin predetermined direction.

. Referring now to Fig. 1, the mercury switches 52, 53 are shown innormal open circuited condition. If the shading coils 31, 38 areunequally energized, thatI is with an overlap of energization onerelative to the other, then a close circuiting of the mercury svn'tch52, or of the mercury switch 53 will result in duration and directiondependent upon the relative energization of thshading coils 3l, 38.

The neutral of the mercury .switches 52, 53 is connected by a conductor58 with one side of the power source l1. The other terminal of lthemercury switch 52 is connected by a conductor 53 with one eld winding6l! oi a reversing motor generally indicated at 6I. The other terminalof the mercury switch 53 is connected through a conductor 62 withanother iield winding 63 of the motor 6I. The neutral from the motor 8lis connected through a conductor 56" with the opposite side of thepowersource l1 through the conductor 32.

The motor 6l is of a reversing type wherein energization of the winding60 or of the winding 53 will cause rotation in predetermined directionand for so long as such winding remains energized. The arrangement andfunctioning of the receiving device 35 is such that both of the windings60, 63 will not be energized simultaneously.

The motor 6| is adapted through the necessary gear reduction toangularly position the vdamper 2 across the conduit l for regulating orcontrolling the pressure of the uid therein effective upon the Bourdontube 3. At the Sametime the motor El is arranged to position a cam B5carry-- ing on its periphery the roller arm end of the pivoted member44. Thus'the position of the cam 65, the motor 6l, and consequently ofthedamper 2, is reflected in the position of the member M andcorrespondingly of the contact arm 43, Likewise, the position of thedamper 'Y emetrically transmitted to a receiver 35 whereV they controlthe energization of the shading coil 31. At the same time thetransmitter 29 cyclically originates signals each of a time durationdependent upon the position of the member M for that proportion of theperiphery of thi cam 30 during which the contacts 55, B1 are closicircuited. Such periodic signals are telemetrical ly transmitted to thereceiver 35 wherein the; control energization of the shading coil 38.

It will thus be seen that the receiving mecha nism 35 is differentiallyresponsive to tlie'signal originating 1n the transmitter vl2 and lothosoriginating in the transmitter 29 and that th signals sent out bythe mercury switches 52, 5

' are in sense and duration the algebraic summa tion of the signalsoriginating in the transmit ters l2, 23. Such signals sent out from there ceiving mechanism 35 are periodic and are tele metrically transmittedto a motor or powe means 6l wherein they control the direction an extentof a movement reflected in the damper and in the cam 65.

The positioning by the power-` means 6I o the damper 2 results in acontrol of the flut within the conduit l and thereby of the variablwhich is instigating and determining the signal at the transmitter I2.At the same time th positioning of the cam 65 determines the signalinitiated at the transmitter 29.

It will further be seen that in effect I have .telemetric system whereina primary transmit ter l2 and a primary transmitter 29 telemetrical lytransmit cyclic signals to a receiver 35 whici is in itself atransmitter differentially responsiv to the signals from thetransmitters rl2 and 2! and itself telenietrically transmitting cyclicsig nais of a direction and duration being the alge braic sum of saidprimary signals. These re sultant signals pass to a receiving power mean6I.

While I have chosen to illustrate vand describ a preferred embodiment ofmy invention, it i to be understood that I am not to be limite s therebybut only as to the claims in view` of pric art.

What I claim as new, and desire to secure b Letters Patent of the UnitedStates, is: v

1. A telemetric system, comprising in combina tion, a rst transmitterfor cyclically telemeterin signals of a time duration corresponding to aiin variable quantity, a second transmitter for cycli cally telemeteringsignals of atirne duration coi responding to a second variable quantity,receive means responsive to said signals, a motor havin two windings,and means controlled by'said rf ceiver means for cyclically energizingone or'tl; other of said windings selectively in dependen( upon therelative time vduration of the signa cyclically telemetered by said rstand secon transmitters.

2. A telemetric system, comprising in combina tion, a first transmitterfor cyclically telemetei ing signals of a time duration corresponding ia rst variable quantity, a second transmitter fr cyclcally telemeteringsignals of a time duratio corresponding to a second variable quantity,rf ceiver means responsive to said signals, a mot( having two windings,and means controlled t said receiver means for cyclically energizing oror the other of said windings for an increment c time corresponding tothe difference in` tirr duration of said signals and selectively indepenc' ence upon the relative time duration' of sai 3. A telemetricsystem, comprising in combine tion, a first transmitter for cyclicallytelemeterln signals of a time duration corresponding tc a r: variablequantity, a second transmitter for cycr cally telemetering signals of avariable time dure windings selectively independence upon the rela- Ktive time duration of the signals cyclically telemetered by said firstand secorti transnatters. a cam positioned by said motor, and meansoperated by said cam for varying` the time duration o1 the signalstelemetered by the second transmitter so as to maintain said signalsequal in time duration to those telemetered by said first transmitter.

4. A telemetric system comprising in combination, a iirsttransmitter forcyclicaliy telemetering signals of a time duration corresponding to afirst variable quantity, a second transmitter for Acyclii callytelemetering signals of a. time duration corresponding to a secondvariable quantity, receiv ing means diierentially responsive to saidsignals and comprising an opposed wound motor having a freely rotatingcam and rotor assembly for actuating pivoted switch members, a motorhaving two windings, and said receiver means cyclically selectivelyclosing a switch member energizing one or the other of said motorwindings in dependence upon the relative time duration of the signalscyclically telemetered by said rst and second transmitters.

5. A telemetric system, comprising in combina- A ation, a firsttransmitter for cyclically telemetering signals of a time durationcorresponding to a rst variable quantity, a second'transmltter forcyclieally telemetering signals of a time duration corresponding to asecond variable quantity', lreceiver means responsive to said signals, areversible motor, and means controlled by said receiver means forcyclically energizing said motor to cause selective operation thereof independence upon the relative time duration of the signals cyclicallytelemetered by said iirst and second transmitters.

y 6. A telemetric system, comprising in combi; tion, a first transmitterfor cyclically telemeter signals of a time duration corresponding to a fvariable quantity, a second transmitter for cy cally telemeterlngsignals of a time duration c responding to a second variable quantity,recei means responsive to said signals, a reversi motor, and meanscontrolled by said recel means for cyclically energizing said motorcause forward or reverse operation thereof an increment of timecorresponding to the t ference in time duration of said sigr-als, andleetively in dependence upon the relative ti duration of said signals.

7. A telemetric system, comprising in combi] tion, a first transmitterfor cyciically telemeter signals of a time duration corresponding to a fvariable quantity, a second transmitter for cy cally telemeterlngsignals of a variable time du tion, receiver means responsive to saidsignal: reversible motor, means controlled by said rece ing means forcyclically operating said motor one direction or the other selectivelyin depel ence upon the relative time duration of the s nais cyciicallytelemetered by said first and s ond transmitters, and means positionedby s motor for altering the time duration of the s nals transmitted bysaid secondtransmitter correspondence with changes in the posit thereof.v

8. A telemetric system, comprising in combii tion, a first transmitterfor cyclically telemeter rst signals. means for adjusting said rsttra:mitter to vary the time duration of said :tirst s nais. a secondtransmitter for cyciicaily te metering second signals, means foradjusting s second transmitter to vary the time duration said secondsignals, receiver means responsive said signals, a reversible motor, andmeans ci troiled by said receiver means for cyclically en gizing saidmotor to cause selective operati thereof in dependence upon the relativeti duration of the signals'cyclically telemetered said first andsecond'transmitters.

Y Y PAUL S.y DICKEY

